Dear Tom and Ray:

Last year a friend gave me a nearly new set of tires for my Toyota Tacoma 4x4. I'm a cyclist who puts about 14,000 miles a year on my bicycles, so I drive very little. At the rate I drive, it might be five years or more before I need to install these tires on my truck. Is there anything I need to do in terms of storage and preservation so these tires are safe to use in the future? Or should I sell them now, while they're still in usable condition? -- James

RAY: All you need to do is store them in your hyperbaric nitrogen chamber, James.

TOM: Even if tires aren't worn out in the traditional way -- by leaving tiny, rubber pieces of themselves on 40,000 miles of roadway -- they still get old. The rubber can dry out and crack, due mostly to ozone that's in the air.

RAY: So, a number of manufacturers now suggest that we all put expiration dates on our tires. Ford, for instance, suggests that you get rid of a set of tires after six years of use, due to atmospheric degradation of the rubber.

TOM: And while cynics would say they're just trying to sell more tires (and, of course, that is a happy side benefit), there is a good body of evidence to back up their recommendation.

RAY: So, if your tires have been on your truck for six years or more (and yours may have been, since you drive so little), you may want to put those newer tires on right now.

TOM: And if not, sell them to someone who can use them now, and use the proceeds to buy yourself some extra-heavily padded bicycle shorts. About 14,000 miles? Ouch!